1
|
Phan CM, Qiao H, Yee A, Jones L. Deposition of Fluorescently Tagged Lysozyme on Contact Lenses in a Physiological Blink Model. Eye Contact Lens 2021; 47:127-133. [PMID: 31789754 DOI: 10.1097/icl.0000000000000683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE To visualize the deposition of fluorescein isothiocyanate (FITC) lysozyme on daily disposable contact lenses (CLs) using a novel blink model. METHODS Three daily disposable conventional hydrogel CLs (etafilcon A, omafilcon A, and nelfilcon A) and three silicone hydrogel CLs (delefilcon A, senofilcon A, and somofilcon A) were evaluated in the study. The CLs were mounted onto a novel blink model and exposed to an artificial tear solution containing FITC lysozyme for 2 and 10 hr. The flow rate and blink speed were set to 1 μL/min and 6 blinks/min, respectively. After the incubation period, a 5-mm-diameter disc was punched out from the center of the lens and mounted on a microscope slide. The slides were imaged using the Zeiss 510 Meta confocal laser scanning microscope, which scanned the lens from the front to the back surface at 5-μm increments. RESULTS There was an increase in deposition of FITC lysozyme for all lens types with increasing incubation time (P<0.05), with the exception of somofilcon A, which did not show statistical significance between 2 and 10 hr (P>0.05). The conventional hydrogel CLs deposited higher amounts of FITC lysozyme than the silicone hydrogel CLs (P<0.001), with etafilcon A depositing the highest at all time points (P<0.05). Interestingly, at the 2-hr incubation time, most CLs showed a higher amount of deposition at the front surface than the back surface of the lens. In particular, etafilcon A showed preferred deposition at the front surface at all time points. CONCLUSION The results suggest that there is differential deposition at the front surface of the CL, which is exposed to the prelens tear film, compared with the back surface of the CL, which is exposed to the postlens tear film. Therefore, it may be beneficial to design CL materials with differing surface properties for the front and back surfaces of the CL to enhance interactions with the tear film and ocular surface.
Collapse
Affiliation(s)
- Chau-Minh Phan
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | | | | | | |
Collapse
|
2
|
Fouling in ocular devices: implications for drug delivery, bioactive surface immobilization, and biomaterial design. Drug Deliv Transl Res 2021; 11:1903-1923. [PMID: 33454927 DOI: 10.1007/s13346-020-00879-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The last 30 years has seen a proliferation of research on protein-resistant biomaterials targeted at designing bio-inert surfaces, which are prerequisite for optimal performance of implantable devices that contact biological fluids and tissues. These efforts have only been able to yield minimal results, and hence, the ideal anti-fouling biomaterial has remained elusive. Some studies have yielded biomaterials with a reduced fouling index among which high molecular weight polyethylene glycols have remained dominant. Interestingly, the field of implantable ocular devices has not experienced an outflow of research in this area, possibly due to the assumption that biomaterials tested in other body fluids can be translated for application in the ocular space. Unfortunately, progression in the molecular understanding of many ocular conditions has brought to the fore the need for treatment options that necessitates the use of anti-fouling biomaterials. From the earliest implanted horsehair and silk seton for glaucoma drainage to the recent mini telescopes for sight recovery, this review provides a concise incursion into the gradual evolution of biomaterials for the design of implantable ocular devices as well as approaches used to overcome the challenges with fouling. The implication of fouling for drug delivery, the design of immune-responsive biomaterials, as well as advanced surface immobilization approaches to support the overall performance of implantable ocular devices are also reviewed.
Collapse
|
3
|
Qiao H, Luensmann D, Heynen M, Drolle E, Subbaraman LN, Scales C, Riederer D, Fadli Z, Jones L. In vitro Evaluation of the Location of Cholesteryl Ester Deposits on Monthly Replacement Silicone Hydrogel Contact Lens Materials. Clin Ophthalmol 2020; 14:2821-2828. [PMID: 33061266 PMCID: PMC7522414 DOI: 10.2147/opth.s270575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/22/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose The deposition profile of cholesteryl ester on the surface and throughout the matrix of silicone hydrogel contact lens (CL) materials was determined under conditions that mimic a daily wear regimen. Methods In this in vitro study, four SiHy CL materials (senofilcon C, lotrafilcon B, comfilcon A and samfilcon A) were incubated in an artificial tear solution (ATS) for up to 30 days. CL incubation was alternated between the ATS (16 hours) and a multipurpose care regimen (8 hours). The ATS included fluorescently tagged cholesteryl ester (5-cholesten-3ß-ol 6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]caproate; CE-NBD) and confocal laser scanning microscopy visualized the distribution of the lipid through the CLs. Results The distribution of CE-NBD was homogenous from the anterior to posterior surface in senofilcon C and comfilcon A, at all time points. For lotrafilcon B and samfilcon A, CE-NBD localization was heterogeneous, with greater amounts on the surfaces on Day 1 and Day 14 compared to the lens matrix; however, differences in concentration between the surface and bulk diminished by Day 30. Conclusion The distribution of the non-polar lipid CE-NBD varied with lens material chemistry. While some lens materials deposited the lipid primarily on the surface after 16 hours of exposure, all materials exhibited a homogenous distribution after one month.
Collapse
Affiliation(s)
- Han Qiao
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Doerte Luensmann
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Miriam Heynen
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Elizabeth Drolle
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Charles Scales
- Johnson & Johnson Vision Care, Inc, Jacksonville, FL, USA
| | | | - Zohra Fadli
- Johnson & Johnson Vision Care, Inc, Jacksonville, FL, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada.,Centre for Eye & Vision Research (CEVR), Hong Kong, People's Republic of China
| |
Collapse
|
4
|
Depth Profile Assessment of the Early Phase Deposition of Lysozyme on Soft Contact Lens Materials Using a Novel In Vitro Eye Model. Eye Contact Lens 2018; 44 Suppl 2:S11-S18. [DOI: 10.1097/icl.0000000000000397] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
5
|
Panthi S, Nichols JJ. An imaging-based analysis of lipid deposits on contact lens surfaces. Cont Lens Anterior Eye 2018; 41:342-350. [DOI: 10.1016/j.clae.2017.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 10/18/2022]
|
6
|
Walther H, Phan CM, Subbaraman LN, Jones L. Differential Deposition of Fluorescently Tagged Cholesterol on Commercial Contact Lenses Using a Novel In Vitro Eye Model. Transl Vis Sci Technol 2018; 7:18. [PMID: 29644148 PMCID: PMC5892225 DOI: 10.1167/tvst.7.2.18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/17/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose We evaluate the differences in lipid uptake and penetration in daily disposable (DD) contact lenses (CL) using a conventional “in-vial” method compared to a novel in vitro eye model. Methods The penetration of fluorescently labelled 22-(N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)Amino)-23,24-Bisnor-5-Cholen-3beta-Ol (NBD)–cholesterol on three silicone hydrogel (SH) and four conventional hydrogel (CH) DD CLs were investigated. CLs were incubated for 4 and 12 hours in a vial, containing 3.5 mL artificial tear solution (ATS), or were mounted on an in vitro eye-blink platform designed to simulate physiologic tear flow (2 mL/24 hours), tear volume and “simulated” blinking. Subsequently, CLs were analyzed using laser scanning confocal microscopy and ImageJ. Results Penetration depth and fluorescence intensities of NBD-cholesterol varied between the incubation methods as well as lens materials. Using the traditional vial incubation method, NBD-cholesterol uptake occurred equally on both sides of all lens materials. However, using our eye-blink model, cholesterol penetration was observed primarily on the anterior surface of the CLs. In general, SH lenses showed higher intensities of NBD-cholesterol than CH materials. Conclusions The traditional “in-vial” incubation method exposes the CLs to an excessively high amount of ATS, which results in an overestimation for cholesterol deposition. Our model, which incorporates important ocular factors, such as intermittent air exposure, small tear volume, and physiological tear flow between blinks, provides a more natural environment for in vitro lens incubation. Translational Relevance In vitro measurements of CLs are a common approach to predict their interactions and performance on the eye. Traditional methods, however, are rudimentary. Therefore, this study presents a novel in vitro model to evaluate CLs, which consequently will enhance elucidations of the interactions between CLs and the eye.
Collapse
Affiliation(s)
- Hendrik Walther
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Chau-Minh Phan
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| |
Collapse
|
7
|
Schuett BS, Millar TJ. An Experimental Model to Study the Impact of Lipid Oxidation on Contact Lens Deposition In Vitro. Curr Eye Res 2017; 42:1220-1227. [DOI: 10.1080/02713683.2017.1307416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Burkhardt S. Schuett
- Western Sydney University, School of Science and Health, Penrith, NSW, Australia
| | - Thomas J. Millar
- Western Sydney University, School of Science and Health, Penrith, NSW, Australia
| |
Collapse
|
8
|
Guzman G, Bhaway SM, Nugay T, Vogt BD, Cakmak M. Transport-Limited Adsorption of Plasma Proteins on Bimodal Amphiphilic Polymer Co-Networks: Real-Time Studies by Spectroscopic Ellipsometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2900-2910. [PMID: 28240027 DOI: 10.1021/acs.langmuir.7b00281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Traditional hydrogels are commonly limited by poor mechanical properties and low oxygen permeability. Bimodal amphiphilic co-networks (β-APCNs) are a new class of materials that can overcome these limitations by combining hydrophilic and hydrophobic polymer chains within a network of co-continuous morphology. Applications that can benefit from these improved properties include therapeutic contact lenses, enzymatic catalysis supports, and immunoisolation membranes. The continuous hydrophobic phase could potentially increase the adsorption of plasma proteins in blood-contacting medical applications and compromise in vivo material performance, so it is critical to understand the surface characteristics of β-APCNs and adsorption of plasma proteins on β-APCNs. From real-time spectroscopic visible (Vis) ellipsometry measurements, plasma protein adsorption on β-APCNs is shown to be transport-limited. The adsorption of proteins on the β-APCNs is a multistep process with adsorption to the hydrophilic surface initially, followed by diffusion into the material to the internal hydrophilic/hydrophobic interfaces. Increasing the cross-linking of the PDMS phase reduced the protein intake by limiting the transport of large proteins. Moreover, the internalization of the proteins is confirmed by the difference between the surface-adsorbed protein layer determined from XPS and bulk thickness change from Vis ellipsometry, which can differ up to 20-fold. Desorption kinetics depend on the adsorption history with rapid desorption for slow adsorption rates (i.e., slow-diffusing proteins within the network), whereas proteins with fast adsorption kinetics do not readily desorb. This behavior can be directly related to the ability of the protein to spread or reorient, which affects the binding energy required to bind to the internal hydrophobic interfaces.
Collapse
Affiliation(s)
- Gustavo Guzman
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Sarang M Bhaway
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Turgut Nugay
- Chemistry Department, Polymer Research Center, Boğaziçi University , Bebek, 34342 Istanbul, Turkey
| | - Bryan D Vogt
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Mukerrem Cakmak
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| |
Collapse
|
9
|
Phan CM, Walther H, Gao H, Rossy J, Subbaraman LN, Jones L. Development of an In Vitro Ocular Platform to Test Contact Lenses. J Vis Exp 2016:e53907. [PMID: 27078088 DOI: 10.3791/53907] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Currently, in vitro evaluations of contact lenses (CLs) for drug delivery are typically performed in large volume vials, which fail to mimic physiological tear volumes. The traditional model also lacks the natural tear flow component and the blinking reflex, both of which are defining factors of the ocular environment. The development of a novel model is described in this study, which consists of a unique 2-piece design, eyeball and eyelid piece, capable of mimicking physiological tear volume. The models are created from 3-D printed molds (Polytetrafluoroethylene or Teflon molds), which can be used to generate eye models from various polymers, such as polydimethylsiloxane (PDMS) and agar. Further modifications to the eye pieces, such as the integration of an explanted human or animal cornea or human corneal construct, will permit for more complex in vitro ocular studies. A commercial microfluidic syringe pump is integrated with the platform to emulate physiological tear secretion. Air exposure and mechanical wear are achieved using two mechanical actuators, of which one moves the eyelid piece laterally, and the other moves the eyeballeyepiece circularly. The model has been used to evaluate CLs for drug delivery and deposition of tear components on CLs.
Collapse
Affiliation(s)
- Chau-Minh Phan
- School of Optometry and Vision Science, University of Waterloo;
| | - Hendrik Walther
- School of Optometry and Vision Science, University of Waterloo
| | | | - Jordan Rossy
- School of Optometry and Vision Science, University of Waterloo
| | | | - Lyndon Jones
- School of Optometry and Vision Science, University of Waterloo
| |
Collapse
|